The present invention relates to methods and apparatus for use in surgical procedures, and in particular to methods and apparatus which can be used intra-operatively to correct or update a planned position for an orthopaedic implant.
Surgical planning software can be used prior to an orthopaedic surgical procedure in order to help plan the intended position and orientation of the orthopaedic implant or implants in the patient's bone or bones. The intention of the surgical procedure is then to actually place the implant at its planned position. However, in practice, the actual position of implantation may vary from the planned position for a number of reasons. For example, in a hip replacement operation, the surgeon may plan to place the stem implant at a certain depth, varus-valgus angle and anteversion angle relative to the femur. However, these planned positions may be compromised by the reaming process resulting in a different implant position intra-operatively.
However, the surgeon may not be aware that the implant has not been placed at the planned position.
Hence, it would be beneficial if the surgeon could determine any variation in the intra-operative position compared to the planned position and so decide whether any corrective action might help bring the implant position closer to the planned position.